PEORIA, Ariz. -- Sean Burnett, the formidable reliever signed to a two-year deal this offseason, had been lying in the weeds all spring, pushed to the background because the Ryan Madson signing was a bigger deal and because a non-threatening back injury sidelined him. To many -- particularly the media, but probably to a lot of his teammates as well -- he's still a bit of a mystery.

This much can be surmised after Burnett's outing on Wednesday, though: He sure is hard on himself.

After giving up two runs on four hits in one-third of an inning against the Padres at Peoria Sports Complex, Burnett had every reason to disregard the results and -- as most guys do -- file it under the process of getting ready for a season. It was, after all, his first outing of the spring. You'd expect rust.

Instead, Burnett was fuming.

"I don't care if it's Spring Training or a pickup game in the driveway," he said. "You want to do your best and put up zeros. Today just wasn't acceptable."

The Angels know they have a great weapon in Burnett, a heavy-sink left-hander who gets a lot of ground balls, is effective against both righties and lefties, can throw full innings and has been a top-caliber reliever the last four years, compiling a 2.85 ERA and a 1.20 WHIP with the Pirates and Nationals.

"He can be a left-handed specialist, he can pitch an inning, he can pitch two innings -- he can do it all, really," said Angels catcher Chris Iannetta, who's quite familiar with Burnett from the catcher's days with the Rockies in the National League.

"Everyone early on battles adrenaline."

Burnett had plenty of it in his spring debut -- perhaps too much. It was his first Cactus League outing since suffering a stiff lower back early in camp, with the team that signed him to an $8 million deal, and the 30-year-old was admittedly "a little geeked up."

"It's been a while since I stepped on the mound, so I was a little jittery out there," Burnett said. "It probably had something to do with being up in the zone a little bit and probably throwing through the [sinker].

Burnett had no problems throwing strikes -- he threw first-pitch strikes and got to two strikes on four of the five batters he faced -- but he had a hard time putting guys away, resulting in four singles and one popup in a 20-pitch outing.

"I'm disappointed in myself," Burnett said. "I'm frustrated. I don't care if it's Spring Training. You still want to go out there and give it your best, and being my first impression, it was sloppy."

"He'll be better," manager Mike Scioscia cautioned.

And there's no reason to think Burnett won't. His track record is sparkling; his back and left elbow, which underwent an offseason procedure to remove bone spurs, feel "100 percent," by his own estimation; Scioscia believes the movement on his pitches is just fine; and there are no doubts Burnett will be ready by Opening Day, barring an unforeseen setback.

But none of that prevented him from being peeved at his unsuccessful spring debut.